Reamer-grinding machine



Aug. 28, 1928.

F. O. ALBERTSON REAMER GRINDING MACHINE Filed June 30, 1926 5 Sheets-Sheet 1 Snven 1% r' Frans 0. A/bc'rfiw/z g 6AM,

in M9 /m.

Aug. 28, 1928. 1,682,459

F. O. ALBERTSON REAMER GRINDING MACHINE Filed June 30, 1926 3 Sheets-Sheet 2 3 n zfcnio r: Frans 0. 416677 30.

Aug. 28, 1928.

1,682,459 F. 0. ALBERTSON REAMER GRINDING MACHINE Filed June 30, 1926 3 Sheets-Sheet 3 1 l1 Alli Patented Aug. 28, 192 8.

UNITED STATES PATENT OFFICE.

FRANS O. ALBERTSON, OF, SIOUX CITY, IOWA, ASSIGNOR TO ALBERTSON & COMPANY,

INC., OF SIOUX CITY, IOWA, A CORPORATION OF IOWA.

BE AMEB-GRIN DING MACHINE.

Application filed June 30, 1926. Serial No. 119,552.

.My invention relates to grinding machines. contemplates the provision of a reamer grinding attachment for small garage type grinding machines.

It is an object of my invention to provide asimple attachment for grinding machines whereby reamers and similar tools may be quickly and accurately ground.

A further object of my invention is to provide improved means for maintaining the reamer in proper position relative to the abrasive wheel to obtain a practical working clearance.

A further object is to provide an improved attachment for a small portable grinding machine which is simple in construction. may be economically manufactured and which may be efiiciently operated by relatively unskilled workmen, to accurately sharpen reamers and similar tools.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which Fig. 1 is a perspective view of the reamer grinding attachment, showing a reamer in position to be ground.

Fig. 2 is a plan view of the grinding machine with the reamer grinding attachment positioned thereon.

Fig. 3 is a perspective View of a -gauge employed in adjusting the tooth rest to ob- 133111 the proper clearance.

Fig. 4 is a vertical section taken on the plane represented by the line 44 of Fig. 2.

Fig. 5 is a similar section taken on the plane represented by the line 55 of Fig. 2.

The grinding machine proper may be of anysuitable construction, but is preferably of the type as shown and described in my co-pending application, Serial No. 718,713, filed June 9, 1924. As shown in Fig. 2,.the grinding machine consists of a base casting 11 upon which a motor 12 and emery wheel 13 are mounted, the mounting for these parts being adjustable relative to the base 11. The emery wheel 13 is carried at the end of a shaft 14 which is rotatable in the bearing 15 and which at its other end carries a pulley 16. The pulley 16 is driven by belt 17 which runs over a pulley 18 ,secured to the motor shaft. An upwardly extending bracket 19 is horizontally bored to receive a rod 21 at the end of which the More particularly, my invention emery wheel guard 22 is fixed. The rod 21 is held in adjustable position in the bracket 19 by set screw 23.

A chuck 24 is mounted on a plate 25, which may be moved toward and away from the emery wheel 13. The chuck 24 is also adjustable through an arc, to lie at any desired angle to the plane of the emery Wheel 13 so as to be adapted to hold drills, valves and similar articles against the emery wheel at any desired angle. Thus far, I have described the grinding machine proper, in order that the nature of my invention, whichconsists'of an attachment to this machine, may be more readily understood.

The attachment comprises a mounting plate 26 which may be secured to the plate 25 by means of a bolt 27 which passes through the drill hole 28 formed in the mounting plate 26. The mounting plate has a downwardly projecting guide 29 which fits into a complementary groove formed in the upper surface of the plate 25, so as to prevent relative rotation between the plates 26 and 25. A pair of cylindrical guides or ways 31 and 32 are secured to. lugs 33, '34, 35 and 36 which project upwardly from the mounting plate, by any suitable means such as screws (not shown). A carriage 37 is slidable over the ways 31 and 32 resting thereon at three points. A projection 38 having a'machined surface bears upon the way 31 while a pair of machined guides 39 and-41 formed integral with the carriage 37 fit over the way 32. The carriage has a pair of longitudinal slots 42 and 43 adapted to receive the'various attachments, as will hereinafter be described. The upper surface has a longitudi-- plate 25 and through a suitable carriage. The carriage is slidably secured tothe-wa'ys by means of a clamping member 46 which has machined surfaces 46* and 46 adapted to contact with the lower surfaces of ways 31 and 32, respectively, A stub shaft 48 is pivotally carried in a pair of lugs 49, on the clamping member 46,

This shaft is diametrically tapped to receive a fillister head cap screw 50. the head of which fits in a recess 51 in the carriage. It will be apparent that upon tightening the cap screw 50 the clamping member 46 will be drawn upwardly, but that due to the fact that the clamping force acts through the centrally positioned shaft; 48 the pressures exerted at the surfaces 46 and -16 are equalized. Lug 59. depending from the carriage 37 fits between the upwardly projecting lugs 49 of the clamping member LG and thus causes the clamping member to slide along the ways with the carriage. A set screw 53 acting through a plug 54 is provided to hold the cap screw 50 in adjusted position. i guard depends from the rear edge of the carriage 37, being secured thereto by means of machine screws 56 threaded into the guide lugs 39 and ell. This guard prevents the emery dust and other foreign matter from being thrown against the ways.

The carriage 37 at the ends of its forward edge carries a pair of lugs 57 and 58, which are longitudinally drilled to receive the headed limiting stops 59 and 61, the stops being adjustably secured to the lugs by means of suitable set screws 62. The heads of these stops are adapted to engage the ends of the way 31 and thus limit the extent of movement of the carriage relative to the way. The various attachments which may be adjustably positioned on the carriage 37 will now be described. The tail stock comprises a bracket 63 which has a machined bottom surface resting on the upper machined surfaces of the carriage and has a suitable guiding projection 64 fitting within the groove 44 of the carriage. The bracket is secured to the carriage by means of a T-headed bolt 65 extending through the bracket and the slot 42 of the carriage, the head of the bolt being prevented from turning by the ribs '45. The bracket carries a center 66, the

position of which may be adjusted and secured in adjusted position by set screw (37. This center will be termed the fixed center and is adapted to extend within the usual countersunk centering hole at the end of the reamer shank. The other end of the reamer 68 is held in an adjustable center which will now be described.

As best shown in Fig. 4, the adjustable center comprises a base plate 69 having a downwardly projecting guiding lug 71 which tits in the groove 44 in the carriage 37. The adjustable bracket 72 is mounted for sliding, movement relative to the base plate 69 in a direction perpendicular to the ways. The bracket 72 has an elongated slot 7 3 through which the stud 74, which is threaded into the base plate (39, passes. A suitable nut 7c and washer 74 are provided for clamping the bracket 72 in adjusted position on the base plate 69. A micrometer adjusting screw 75 is threaded in the bracket 72, being rotatably mounted in a plate 76. and held against axial movement therein by a squared collar 77, pressed over or formed integral with the screw, and a sleeve 78. The plate 76 is fixed to the bracket 72. Sleeve T8 is held in abutting engagement with collar 77 by a knurled nut 79 threaded upon screw 75, the nut also serving to clamp a dished indicating dial 81 between it and the sleeve. The knurled nut 79 preferably has a squared portion 83 so that these parts may be easily and securely clamped togcther. The dial 81 is suitably graduated. the graduations being adapted to be brought in register with a scratch mark upon the top surface of the plate 76. The sides of the plate 69 and the bracket 72 have marks OO (Fig. l) to indicate the normal position of the bracket.

The rear eml of the bracket Til carries a centering pin 8% which may be secured in adjusted position by the set screw The base plate 69 has a side lug 86 (Fig. 2) which is drilled to receive a T-hcaded bolt 8? extending through the slot 43 in the carriage and thus serves to secure the adjustable center assembly to the carriage in any desired position along the slot.

A tooth rest bracket 88 (Fig. 1) may be secured in adjustable position on the carriage 37 by means of a T-headed bolt 89 in a manner similar to that employed in securing the centering brackets. The upper end of this bracket is horizontally drilled to receive a rod 91 which may be secured in adjusted position by means of a set screw 92. The end of the rod 91 is enlarged and diametrically drilled to receive the tooth rest 92 which may be shifted relative to the rod 91 and secured in any desired position by set screw 94 threading into the end of the rod 91. The tooth. rest 93 comprises a cylindrical portion which is slidable in the rod 91 and a flattened guide strip 95 which is lixed in the cylindrical portion. This strip is preferably made of hardened steel and has its lower end conformed to serve as a guide for the cutting edges of the reamer. as will later be described.

If desired, the bracket 88 may be eliminated and the tooth rest 93 supported from a bar 96 (Fig. 2) which is secured to the rod 21 by means of a set screw 97 and is drilled and slotted in a horizontal plane so that the rod 91' may be clamped therein by tightening of the screw 98.

In Figure 3 I have shown a gauge 99 which may be used to adjust the height of the tooth rest 93. The bottom surface of this gauge is finished and is adapted to rest upon the upper plane surface of the carriage 37. The end of the gauge bar 99 has a hardened plate 100 secured thereto. The upper edge of this plate serves as the edge upon which the end of the 'guide strip 95 is positioned when adjusting the height of the tooth rest working clearance. A dog 102 is provided may be positioned by means of the microm-" cutting edges of the reamer.

with a plurality of set screws 103 by means of which the dog may be secured to the shank of the reamer. When the reamer is held between the centers it may be freelyturned by manual rotation of the dog 102.

Although the operation of the attachment above described may have appeared from the description, a brief rsum of the sequence of operations will be given. The reamer grinding attachment is first secured to the grinding machine by tightening the nut on the bolt 27. In grinding straight reamers the tooth rest bracket 88 is preferably employed while the tooth rest supporting bar 96 is necessary in grinding spiral reamers. The proper tooth rest bracket is attached and the tooth rest positioned at the proper height as determined by the gauge 99. The fixed and adjustable centers are then properly positioned along the carriage 37 and the reamer to be ground inserted in position betwgen'the centering pins, the dog 102 havmg reamer. The limiting stops 59 and 61- are then adjusted so that the carriage willtravel a sufficient distance to permit the abrasive wheel to grind the desired length of the The adjustable center is set so that the"O marks on the base plate 69 and bracket 72 coincide. The toothrest engages the forward surface of one of the cutting edges of the reamer. The set up being ready for the grinding operation, the motor switch is turned on and the abrasive wheel brought up a ainst the reamer to take the desired"cut. The operator preferably grasping the dog in hisleft hand and one of the brackets in his right, proceeds to slide the carriage back and forth on its ways, in the meantime holding the forward surface of the cutting edge of the reamer being ground against the end of the tooth rest 95. The adjustable center eter screw to secure the desired taper upon the cutting edges of the tapered reamers and several cutstaken to obtain the required lead.

If a spiral reamer is being ground (Fig. 2), the operator will, of course, rotate the reamer in the centers so as to maintain the forward surface of the cutting edge in firm contact with the end of the tooth rest as the reamer is moved longitudinally past the grinding wheel.- The guide strip 95 is sufiiciently resilient so that after one of the edges has been ground the next cutting edge may be turned past the tooth rest so as to place it in position for grinding. .In grinding rst been secured to the shank of thev expansion reamers, the expansion screw of the reamer is removed and a large conical headed center 105 (Fig. 1) is inserted in place of the expansion screw.

It will be seen that the grinding attachment of my invention affords a simple and inexpensive machine for accurately and g uicklygrinding reamers of various t pes.

he parts may be quickly set up an re moved from the grinding machine, andtheattachment may conveniently be stored away when not in use.

While the form of mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form of embodiment herein disclosed for it is susceptible of embodiment in various forms, all coming within follow.

I claim 1. Ina machine of the class described, the combination of a mounting plate, a pair of parallel spaced cylindrical ways secured thereto, a carriage slidable over said ways, and means for securing said carriage to said ways comprising a clamp having a pair of :upwardly extending lugs adapted to fit a downwardly .projectin a shaft passing throng rotatable therein, and a lug on said carriage, said clamp lugs and cap screw seated in said carriage and threaded diametrically;

through said shaft whereby said clamping member may be drawn toward said carriage, said shaft forming an equalizing means to distribute the clamping force between said ways.

2. In a reamer grinding machine, the combination of a mounting plate adapted to be attached to a grinding machine; spaced upwardly extending lugs at each end of said plate; parallel cylindrical guides carried by said lugs; a carriage mounted on said guides and adjustable thereon, the under side of said carriage being angularly grooved adjacent one edge to engage one of the guides, and formed adjacent its other edge with a plane supporting surface adapted to rest upon the other guide; a clamping member beneath said guides; upwardly projecting lugs on said clamping member; a stub shaft the scope of the claims which carried by said lugs; and screw means passfor contact with the other guide whereby the slide will be supported at three lines of contact with the guides; a clamping member for the slide comprising a plate adapted to 5 contact the under surfaces of said guides and bridge the space therebetween, up-

wardly extending lugs on said clamping member,

axially of the clamping plate, passing through holding the slide in a stub shaft carried by said lugs and means said shaft and slide for 10 contact with the guides.

In Witness whereof, I hereunto subscribe my name this 26 day of June, 1926.

FRANS O. ALBERTSON. 

